How to Permanently Change Command Prompt in Windows 7

Not on a System file.

You could unhide the Administrator account, log into that account, then you don't need to use the "run as admin" on any program, it is done by default.

EDIT

Possible Solution:

Right click on cmd shortcut, select Properties, go to shorcut tab, hit advanced button, tick "Run as administrator", hit OK,OK.

Use the User Environment variables.

Right Click Computer --> Properties --> Advanced Settings --> Advanced --> Environment Variables

In the User variables box click "New..".

Name the variable "Prompt" (without quotes), and set it's value to what you want the prompt to be (refer to "prompt /?" at a command line).

OK --> OK

Open a command prompt (cmd) and it should use that prompt.

Tested in Windows 7, and it still works like it did in NT 4 :)

Hope that helps...